Waterproofer and bond for concrete



Patented Mar. 13, 1934 UNITE STATES PATENT FFICE Raymond W. Bowman, Indianapolis, Ind.

No Drawing. Substitute for abandoned application Serial Ne. 315,932, October 29, 1928. This application August 17,

4 Claims.

This invention relates to water proofing concrete. v

The chief object of the invention is to make a concrete surface substantially water tight or to bond two concrete surfaces together with a substantially water tight joint.

The chief feature of the invention consists in the accomplishment of the foregoing object by preparing a suitable material, and preferably in a predetermined manner and of selected ingredients or their equivalent and in substantially predetermined proportions, following which preparation, the material is applied to the concrete in a suitable manner and under predetermined conditions. Y

In instances where concrete is to be added to concrete it heretofore has been substantially impossible to secure a substantially water tight bond between the two abutting portions of concrete in the joint if the joint be exposed to moisture or the atmosphere. In foundation work particularly this lack of a water tight joint or bond has been a problem long recognized as diilicult of solution. Another problem similarly recognized as difficult of solution is the water proofing of concrete surfaces which are exposed to hydrostatic pressure, and this condition particularly obtains in foundation work. The present invention in addition to solving the aforesaid problems is also capable of filling with a water tight filler cracks or fissures such as might obtain in the walls in the settling of a foundation or wall, or might be found at the junction between a cellar floor and the basement wall immediatelyadjacent thereto.

The present invention, therefore, constitutes a permanent solution to the foregoing problems in counter distinction to temporary solutions.

It has been determined by experiment that a mixture containing substantially one-half ounce of hydrated lime, one ounce of sal ammoniac and one pound of powdered or comminuted grey iron is satisfactory. If desired, to increase the bulk without materially reducing the strength of the bond coating or joint formed thereby, there may be added as much as one-half pound of sand to each pound of iron and still obtain satisfactory results.

The following conditions should be observed in the preparation of the material. It has been determined that the grey iron particles must be substantially free from oil so that borings and other iron material must be cleaned if utilized and the iron should be in such a size that it will pass a sixteen mesh screen. The iron of this character is placed in a mixer and the hydrated lime in 1931, Serial No. 557,739

the proper proportion is added thereto and mixed therewith. There'is apparently no reaction from this mixture. Powdered and dry sal ammoniac in the proper proportion is then preferably mixed with dry sand in the proper proportion without,

any chemical reaction resulting therefrom. The addition of sand to the sal ammoniac increases the bulk of the essential ingredient so that when the sand and sal ammoniac is mixed with the iron and lime a substantially uniform distribution obtains throughout the mixture of the several in:

ency to burn up in the sense that it dusts out, as this word is commonly employed in the concrete art. If an excess of iron is employed the material is relatively slower in setting. The material previously described cannot be employed except in the presence of moisture and air and with the temperature above freezing.

The initial set of the material takes place in from two to three minutes after application to the concrete surface and final set or suitable hardness obtains within twelve hours so that additional coatings of the same or other material can be applied thereto and bonded to the old concrete by it after this period.

In the employment of this material the following precautions must be noted. The hydrostatic pressure, if there be any, must be, preferably, temporarily eliminated either by applying the material under pressure and holding it until the initial set obtains or by employing a temporary filler and removing the pressure in this manner.

The concrete to be covered, if it is to be water proof, or the concrete fissure, if it is to be filled, or the joint between old pieces of concrete or between two new pieces of concrete, or between an old and a new piece of concrete, is first saturated with water prior to the application of the bonding material before mentioned thereto. Without the application of water previous to the application of the material, the material will not set up and bond but will crumble and slough or dust ofi. The material is mixed with a sufficient amount of water and applied to this wet concrete surface or surfaces substantially covering said surface or filling the crack or joints between the surfaces and permitted to set. In about ten to twentyfour hours, depending upon atmospheric conditions, and thickness of application, the surface looks like it was sweating and beads of rusty water appear and subsequently dry out. A layer from 1 5" to /3" is usually sufficient for waterproofing or bonding. A brush coat requires but a few hours to sweat but is not usually used because it is insuflicient to waterproof and secure bond. An additional coating thenmay be applied to the first coating and this may be of the same material, or a cement finish coat may be applied thereto, in either event the first mentioned coat of material or the joint must be thoroughly wet otherwise no bonding will take place.

In applying the material care must be taken when plastering is applied to a surface waterproofed as aforesaid, which plaster may be of the lime or cement type, to be certain that no part of the plaster comes in direct contact with the concrete to be covered. This is to be particularly guarded against where the floor meets the wall. Wherever such contact occurs the connecting portion of the outside coat will serve as a wick or channel through which moisture is drawn from the concrete to be water proofed to the finished or dry coat.

The invention therefore consists in, first, the formation of a material having certain ingredients or their equivalents, secondly, the formation of certain material in a predetermined manner for universal application, and thirdly, the application of this certain material under controlled conditions. The coating formed by this material or the joint after it has set has a brownish color and appears somewhat granular in physical appearance. It looks like rusty sand.

Merely by way of explanation the following is submitted, although it may be possible that the explanation is not correct. Concrete contains caustic soda which is carried to the surface by moisture passing through the concrete and this moisture may come through cracks or through the concrete itself when subjected to suificient hydrostatic pressure. This caustic soda, or whatever it is that is discharged from the concrete, reacts with the sal ammoniac and the lime and the iron to form a bond that has sufficient strength to maintain itself. It also has sufficient strength to maintain a certain amount of sand and incorporate the same as before suggested. In the presence of water and the discharge from the concrete, the lime, sal ammoniac and iron react to form a bonded material that has a bonding afiinity for the concrete adjacent thereto.

While hydrated lime is smoother and finer, commercial lump plasterers lime, or air slaked lime, may be employed instead.

The invention claimed is:

1. A composition including as active ingredients only sal ammoniac, hydrated lime and substantially oil free comminuted grey iron in such proportions as to form a water proof bond with concrete.

2. A composition including as active ingredients only sal ammoniac, hydrated lime and substantially oil free comminuted grey iron and sand in such proportions as to form a water proof bond with concrete.

3. A composition including the following ingredients in approximately the proportions set forth, one ounce of sal ammoniac, one-half ounce of hydrated lime, and one pound of substantially oil free comminuted grey iron, which forms a water proof bond with concrete.

4. A composition including the following ingredients in approximately the proportions set forth, one ounce of sal ammoniac, one-half ounce of hydrated lime, one pound of substantially oil free comminuted grey iron, and about one quarter pound of sand, which forms a water proof bond with concrete.

- RAYMOND W. BOWMAN. 

